Joe's Branch tributary in Spanish Fort gets $1 million makeover

View full sizeStormwater funneled into a small tributary of D'Olive Creek has caused massive erosion of the creek banks. In some places, the creek has cut a gully about 15 deep through the forest. The creek channel and surrounding wetlands have been overwhelmed with sediment, and clay and sand have spread far into the woods. A project worth nearly a million dollars will remove the mud and redesign the creek to better handle stormwater. (Press-Register/Ben Raines)

SPANISH FORT, Alabama -- A tiny tributary in Spanish Fort, a creek so small that a child can step across it, is about to get a makeover worth nearly a million dollars.

The creek’s natural banks disappeared long ago, buried under a massive, 100-foot-wide swash of mud and sand that inundated wetlands in the floodplain and spread out into the surrounding forest.

The sand-filled wetlands and creek can no longer fill their roles as wildlife habitat, which led to the creek being designated a 303d stream. That means federal officials consider it impaired.

While many are familiar with the problem of muddy runoff flowing off of construction sites and into wetlands, rivers and Mobile Bay, the problem in Joe’s Branch is different.

Continued development in the area around the creek has changed the way rainfall travels across the ground after it falls from the sky.

Instead of slowly filtering through the grasses and leaves on the forest floor, all the rain that falls in the area around Spanish Fort Elementary and the Bruno’s Grocery on Alabama Highway 31 is channeled into storm sewers and drainage ditches that flow into the tributaries of Joe’s Branch.

The gathered stormwater flows out of culverts and hits the stream with the force of a fire hose. Stream experts say the funneled stormwater has turned the creek into a flash flood system, subject to brief but intense bursts of water that overwhelm and erode the old stream channel. Scientists call the process “headcutting,” in reference to the way the stream cuts deeper and deeper into the earth.

Tributaries of Joe's Branch, which flows into D'Olive Creek, have been overwhelmed with sediment after stormwater flows eroded the creek banks. The area to be restored is across the street from the Bruno's Grocery store in Spanish Fort. The banks of other Joe's Branch tributaries are also heavily eroded and dumping mud into Mobile Bay. (Courtesy of Mobile Bay National Estuary Program)

Evidence of that erosion is inescapable. The bed of small creeks like this one should be about a foot below the surrounding ground in the forest.

During a Thursday visit, the bed of the creek was more than 10 feet below the surrounding forest in some places. The deep and ever widening gully is working toward U.S. 31 itself, threatening to undermine the roadway, officials with the Alabama Department of Transportation said.

“This drainage issue has been on our radar, as the headcut keeps coming back toward Highway 31. It could eventually reach the road,” said Vince Calametti, district engineer for the transportation department, which contributed $200,000 to the project.

The bulk of the funding, an additional $650,000, comes from the Alabama Department of Environmental Management. ADEM’s Scott Hughes said the agency’s goal was to fund a project that would improve the water quality in Joe’s Branch.

“We try to get landowners to let us do things on their property, best management practices, that will restore water quality and get that stream off the 303d list,” Hughes said. “The department doesn’t have funding to repair every waterway in Alabama, but with demonstration projects like this we can show people techniques that work.”

In the case of Joe’s Branch, the issue is the heavy load of sediment filling the creek. Heavy loads of mud flowing into streams smother aquatic creatures and kill aquatic vegetation. The mud continues its destructive work as it works its way downstream. Mud flowing into Mobile Bay from Daphne is largely to blame for the loss of aquatic vegetation along the Eastern Shore, scientists say.

Sand and mud eroded from the banks of a small tributary of Joe's Branch have buried the creek channel and surrounding wetlands. Mud has spread deep into the forest around the creek and flows toward Mobile Bay with every rain. (Press-Register/Ben Raines)

“There’s a lot of work to be done in that watershed. If we could stem some of this bleeding of sediment into the bay, it would help with the submerged aquatic vegetation,” said Roberta Swann, head of the Mobile Bay National Estuary Program.

Swann spearheaded the effort to address erosion in Joe’s Branch and D’Olive Creek. For this project, she enlisted the cities of Daphne and Spanish Fort and four state agencies: ADEM, the Transportation Department, the Alabama Department of Conservation and Natural Resources, and the Geologic Survey of Alabama.

The Dauphin Island Sea Lab is also contributing environmental expertise and help with administering the various funding grants.

“The restoration is important, but being able to channel the resources of two cities, a private landowner, and four state agencies, that’s big,” Swann said. “Hopefully we’ll set the priority for how we deal with other challenges in our watersheds. The important thing here is we are not just heaping rocks into the creek, armoring it, to handle erosion. ”

The plan to restore the creek centers on slowing the water down as it enters the tributaries. A system of stair-step pools will be constructed in the deep gully.

The pools serve multiple functions, primarily acting as a series of check dams that will rob the water of velocity as it tumbles from one pool to the next. After the rain, the pools will also hold a good deal of water, both allowing sediment to drop out and water to seep back into the ground.

Calametti said the transportation department was eager to see how the pool system worked.

“This low impact development is a coming means of restoring roadways,” Calametti said. “It’s new to us, and we’re really anxious to see how this works.”

Swann said her group also planned to lead classes for homeowners on constructing rain barrel systems for watering gardens and other techniques for trapping water on their properties.

“We want to highlight to people how they can manage stormwater on their property,” Swann said. “The less that runs off their property, the less trouble we’ll have managing these streams.”